@Aron, wow, from your initial post I thought I was giving advice to an aspiring undergraduate, glad to realize I'm talking to an expert :-)

Personally I continually bump up against performance limitations. This is often due to bad coding on my part and the overuse of Matlab for loops but I still have the strong feeling that we need faster machines. In particular, I think full intelligence will require processing VAST amounts of raw unlabelled data (video, audio, etc) and that will require fast machines. The application of statistical learning techniques to vast unlabeled data streams is about to open new doors. My take on this idea is spelled out better here.